The present invention relates to a measuring member allowing for measuring changes in volume of the blood present in the gastrointestinal tract, in which the measured changes in volume are a measure of the blood flow of the gastrointestinal tract and its course in time. In the medical world, measurements of volume changes in organs and/or body parts as a result of their blood flows are known under the term plethysmography.
Methods for determining the blood flow of the gastrointestinal tract are known per se, namely: indocyanine green clearing, stomach tonometry, videoscopy of the tongue blood flow and determination of the oxygen saturation of the large intestine. The most significant disadvantage of these methods is that they are either indirect methods in which the final result is only obtained after some time in the laboratory, or experimental methods, which have not yet been validated. Additionally, the reliability of these methods is not very high, certainly where it concerns determinations in or at body parts and/or organs of which the direct relation to the gastrointestinal tract is not convincing.
However, in severe situations, it is of great importance to be able to know immediately how the blood flow of the gastrointestinal tract is. Here, one can think of e.g. patients being in shock, by whatever cause. In case of a shock, there is a redistribution of the blood flow to the vital organs such as the brain, heart and muscles, causing a reduced blood flow in other organs, including the gastrointestinal tract. If such a situation lasts too long, this can cause a significant deterioration in the function of the gastrointestinal tract, which may lead to a further deterioration in the general physical condition of the patient. The described process can go very quickly and may result in death of the patient. The process can be influenced by medicaments, in which, however, it is of great importance that the effect(s) of said medicaments can be determined immediately.
Apart from the shock condition, in many other situations too it could be very important to be able to monitor the blood flow of the gastrointestinal tract in real time. Here, one can think of an operating room and Intensive Care, where the blood flow of the gastrointestinal tract can be immediately compared to the heart performance (cardiac output) and the treating physician can act directly and adequately on the basis of those data.